The present invention relates to an implantable medical prosthesis for delivering precise doses of medication to selected tissues and in particular, to an implantable prosthesis for supplying medication to the body to stimulate a natural penile erection.
Therapeutic success has been widely reported, in the last decade or so, for the injection directly into the penis of certain nerve blocking agents which permit normal body functions to stimulate dilation of the blood vessels in the penis, thus causing the arterial pressure by which an erection is created.
A broad discussion of this subject and of the chemical compositions effecting penile erection is to be found in U.S. Pat. No. 4,127,118 in which use was made of a dual barrel hypodermic device by which the selected vasodilator is injected from the exterior of the penis directly into the corpora cavernosa.
While improvement in the chemical agents have been made as reported on in more recent medical journals, little improvement, if any, has been made in the apparatus by which the agents are injected into the penis. The use of an external hypodermic device has several disadvantages, particularly amongst which is the pain caused to the user each time an injection is made. Another disadvantage lies in the absence of surety that the necessary specific dose is delivered in precise manner directly to the corpora canervosa so that a natural erection can be had. Still another disadvantage lies in the fact that the injection must be made sufficiently prior to the initiation of coitus so as to avoid interruption or to avoid any psychological reluctance in the presence of the female partner. It is not infrequent that the injection is made so early that its effect has dissipated before successful coitus.
It is the object of the present invention to overcome the disadvantages found in the prior art devices and to provide means by which precise doses of vasodilators can be easily and effectively delivered to the corpora cavernosa in a timely and on demand manner.
It is a specific object of the present invention to provide an implantable prosthesis from which precise doses can be delivered to the penis without repeated injection.
It is another object to provide an implantable prosthesis capable of holding and delivering repeated doses of chemical agents over an indefinite time period, and which is capable of heing refilled periodically.
It is another object of the present invention to provide an implantable prosthesis in the form of a dosimeter capable of delivering precise doses or calculated amounts of chemical agents by hand manipulation by the user alone.
These objects and advantages together with numerous other advantages will become apparant from the following disclosure of the present invention.